Five different types of high-power, low-energy laser pulses have been used to evaluate the damage threshold of plastic and glass intraocular lenses and plastic membranes. The lenses have been studied in air and immersed in water or saline. The threshold damage lesions occur at approximately the same energy density in air and in water. Membrane damage occurs at a slightly lower threshold than lens damage. Membranes can be opened without damaging adjacent lenses. These observations are applicable to materials damage that may occur during trabecular meshwork treatment in glaucoma patients.